<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
    <input type="text" v-model="n1">
    <input type="text" v-model="n2">
    <input type="button" value="加" @click="f(1)">
    <input type="button" value="减" @click="f(2)">
    <input type="button" value="乘" @click="f(3)">
    <input type="button" value="除" @click="f(4)">
    <h1>结果:{{result}}</h1>
</div>
<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<script>
    let v = new Vue({
        el: "body>div",
        data: {
            result: "", n1: "", n2: ""
        },
        methods:{
            f(x){
                switch (x) {
                    case 1:
                        v.result = v.n1*1+v.n2*1;
                        break;
                    case 2:
                        v.result = v.n1-v.n2;
                        break;
                    case 3:
                        v.result = v.n1*v.n2;
                        break;
                    case 4:
                        v.result = v.n1/v.n2;
                        break;
                }
            }
        }
    })
</script>
</body>
</html>